Vice President Gore's political team, acknowledging there is no quick end in sight to the war in the Balkans, is bracing for a presidential campaign eclipsed by an international crisis that was not of his making but could hold his fate.

Gore had hoped to spend the next 18 months building on the domestic successes of the Clinton administration -- touting the booming economy, calling for reviving public education and offering a grab bag of proposals aimed at easing the strains of middle-class life.

Instead, he faces the prospect of defending a complex military and humanitarian effort that White House officials predict will be a defining moment for the Clinton presidency.

But if Kosovo is Clinton's legacy, will the war be Gore's campaign?

"From Gore's perspective, they better win the war," said Robert Zoellick, president of the Center for Strategic and International Studies and a former Bush administration official. "If Clinton and his team are not successful in prosecuting the war, it will just emphasize to a higher degree people's frustration with his leadership, and I'm afraid Gore will inevitably be hurt by that."

For Gore, the war in Kosovo is at best a distraction from more popular issues and at worst could drag the vice president into a quagmire.

"It is becoming more of a reality that we will be campaigning through the primaries with troops fighting door-to-door in Kosovo," said one top adviser. "The preface to every campaign stop will be Kosovo." Said another Gore ally: "Of course he's in a bind; the very nature of being in the vice presidency means you're in a bind. You're basically dealing with the president's issues."

As the air raids over Yugoslavia enter a second month, Gore again finds himself grappling with the dual -- and often competing -- roles of dutiful No. 2 and presidential aspirant. Because of the enormous stakes in Kosovo and the quickening pace of the presidential campaign, the political tensions are particularly acute for Gore.

"It is looking increasingly like Al Gore may become the Hubert Humphrey of the year 2000," said Larry Berman, a senior fellow at the Woodrow Wilson Center, referring to the difficulty Lyndon B. Johnson's vice president had in distancing himself from the administration's Vietnam policy in 1968.

But Gore national security adviser Leon S. Fuerth sees a significant difference with the Kosovo intervention. "To an unusual degree among vice presidents, he's shaped that policy," said Fuerth. "I don't see he is under tension to depart from it; he is in the cockpit."

Both in White House deliberations and in his public statements, Gore has firmly opposed placing ground troops in Kosovo, a position some have interpreted as a political consideration that unnecessarily limits NATO's military options.

Gore campaign manager Craig Smith acknowledged Kosovo may intrude on the campaign, but he stressed: "Kosovo policy, as it should be, is set at the White House; the political consequences shouldn't be factored in."

Fuerth, meanwhile, left open the possibility of revisiting the need for ground troops. "The vice president does not have a static view on this but a running inventory of where we are," Fuerth said.

Joseph Nye, dean of Harvard's Kennedy School of Government and an informal Gore adviser, said comparisons to Humphrey underestimate Gore's role inside the White House. But he acknowledged Kosovo presents other campaign challenges. "It becomes a powerful distraction," Nye said. "It means the agenda is being set and he's not able to set it."

And Gore finds himself competing on turf traditionally more hospitable to Republicans. A recent Washington Post-ABC News poll found Americans preferred Republicans 46 percent to 38 percent on the handling of foreign affairs.

"We're now in a phase where people get up in the morning and talk about foreign policy," one Gore campaign adviser said, conceding the disadvantage. "It doesn't cut as well for Democrats; this is not an issue we lead 3 to 1 on."

Gore's opponents have seized the opening, talking tough on Kosovo and criticizing the administration's management of the crisis. This week, for example, Republican Elizabeth Dole called for positioning ground troops in the region and labeled Yugoslav President Slobodan Milosevic a war criminal. Gore, holding out some hope for a negotiated settlement, has ducked the question of whether he is a war criminal.

He has to, one aide said: "He's trying to keep all options open; if you label him a war criminal, it closes an option."

All presidential candidates face a threshold question: Do they seem plausible as commander in chief? In that sense Gore's ability to demonstrate his military and international expertise could help his campaign.

"This is an opportunity to help fill in the picture of how he would function as our foreign policy leader," said Gore adviser and Harvard Law School professor Christopher Edley, who refers to Gore, a Vietnam veteran, as the "vice commander in chief."

Gore has been out front for the administration since the beginning of the airstrikes, and that effort was on display again Wednesday in a speech at Ellis Island in which Gore argued that America and its NATO allies have both strategic and moral interests in Yugoslavia. "We will roll back Milosevic's reign of terror -- and we will not stop until he withdraws his forces, allows the refugees to return, and accepts an international security force to protect all Kosovars," Gore said.

And it was Gore, not the president, who announced plans to accept 20,000 Kosovo refugees into the United States.

"In this administration he plays a full partner role with the president on foreign policy issues," said former secretary of state Warren Christopher, who noted that part of the reason for tapping Gore in 1992 was his international expertise. "His deep experience is bound to become more evident as foreign policy emerges as a major campaign issue," Christopher predicted.

Moreover, administration officials say they fully expect the airstrikes to be successful and that Gore will rightfully deserve the credit with Clinton for standing up against aggression under intense criticism.

Yet even if the air raids intimidate Milosevic into submission, American soldiers will remain in the volatile region for months if not years helping oversee the reconstruction of Yugoslavia and the return of refugees. That means an issue that will remain through the primaries and possibly the general election.